Emily - nice to hear you are happy with the results of our searches.
Of course we have not yet made a positive identification but I do think we are getting closer.
I just wish I had access to more information for Perranarworthal but it is one Parish where I am sadly lacking.
Now - I have also had a look to see if I could find death records for William and Mary Jane but, like you, with no result.
But I have found them in the 1911 Census! ;D
I only have access to the very bare details but it appears they were probably still living in the same place.
In 1901 the family was at Millbrook in the St German's District.
In 1911 we have William TRAHAR age 58, Jane age 60, Frank age 21 and Lily age 17 living in the St German's District so it is undoubtedly them.
Apart from those already discussed I have another reason for believing the William from Sennen is out of the equation.
The family you are dealing with seems to consistantly spell the name as TRAHAR all the way through the time period we have been looking at.
The Sennen family, no matter where they were, seem to just as consistently spell their name TRAHAIR.
Another option for you to try in your search for death/burial information for William and Mary Jane would be to try the Online Parish Clerk.
I know the information is not available online at their site but you could send them an email with your request.
You could try the OPC for St German's first.
If they don't actually cover Millbrook then they should be able to point you in the right direction.
I have dealt with a few of these people and they have always been very helpful so definitely worth a try.
If you are not sure, or do not know, how to contact them just let us know and we will point you in the right direction.
Now - I have something else that might be interesting that I am having a look at so will post the results in a following note.
CT